Improvement in sewing-machines



UNITED STATES 1 PATENT OFFICE.

NVARREN MILLAR, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN SEWING-MACHINES.

Specif cation forming part of Letters Patent No. 41,527., dated February9, 1564; autedated4 February f3, 1864.

To all whom 'it may concern.:

Be it known that I, WARREN MiLLAR, of Chicago, in the county of Cook andState of Illinois, have invented anew and useful metllod or means ot'supporting the bobbin containing the interlocking thread and of checkingor controlling the loop of needlethread in a rotating-hooksewing-machine; and I do hereby declare that the following is a full,clear, and exact description of the construction and operation of thesame, reference being had tothe annexed drawings, making part of thisspeciiication, and to the letters of reference marked thereon.

Figure 1 is a face view of the slide-ring used on rotatinghooksewing-machines to hold the bobbin containing the interlocking thread inthe excavation in the face of the rotating-hook disk. Fig. 2 is a sideelevation ot' the slidering. Fig. 3 is a birds-eye view of the rotatinghook, slide-ring, and bobbin. Fig. 4 is a front elevation ofthe rotatinghook, slide-ring, and bobbin, and section of cloth-plate andneedle-arnn, part ot' the slide-ring being broken away.

Rotating-hook sewing-machines are now in such .common use that nearlyall mechanics and operatives are familiar with their 0peration. lt willAonly be necessary, therefore, to describe my improvement and its modeof operation to enable others to make and apply the same.

ln rotating-hook sewing-machines the hohbin containing the interlockingthread rests in an excavation in 'the face ofthe rotating-book disk. Therapid motion of the rotating hook during the process ot' sewing causesfriction on the bobbin, and thereby tension on the thread. The tensionthus made is too strong for thin elastic or sleazy goods, making theline of sewing liable to pucker and break. To

.obviate this objection is one object of my in- Ven tion.

In rotating-hook sewing-machines somel method is necessary for checkingor controlling the needle-thread after it has been extended by the hook,to enable the hook in its rotation to pass out of the loops of thethread without becoming entangled therewith. The most successful devicesheretofore used either wear out and require readjustrnent or are extpensive and difficult to construct and apply.

a, Figs. l` 2, and 3, is a strap of thin steel, fastened to theslide-ring, forming a socket in which the heel of the bobbin titsloosely. b is a shelt on which the bobbin rests.

c is asmall projection to prevent the bobbin being drawn upward andjamming between the top ofthe slide-ring and the rotating hook.

r is the slide-ring; m, the bobbin ;p, the rotating hook. At thejunction ofthe ring with its base the neck of the slide-ring iscut intoat h, Figs. l and 2, for a short distance on each side and the ringtwisted about one-sixteenth of an inch, so that the heel ofthe bobbinwill be removed that distance from the excavation in the hook-disk, andthe 'front edge of the. bobbin will project farther into the excavationof the disk, as shown in Fig. 3. The heel of the bobbin is sustained onthe ring by the shaft b and strap c, the strap c forming a socket forthe heel ot' the bobbin, Figs'. 2 and 3, the front edge only of thebobbin resting lightly against the back ofthe excavation in thehookdisk, Fig. 3. By this method of supporting the bobbin it is almostentirely released from friction, and a machine can be run with much lesstension on the upper thread than is possible when the bobbinisvsupported in the exeavated disk, as heretofore. As the needlethreadis extended and passed under the bob` bin by the rotating hook that partot' the loop of thread passing on the front side and lower edge of thebobbin (see Fig. 4, thread shown in red) comes in contact with the strapa, and is there held in the angle `formed by the heel of the bobbin andthe strap a until the point of the hook has passed out of the extendedloop and has entered and begun to extend a new loop from the needle.(See Fig. 4.) Pulling the loop of thread backward and upward toward theperiphery of the rotating hook,

presses the bobbin against the strap a, and the thread will beheldfirmly in the angle formed by the heel or' the bobbin and theA edge ofthe strap a. (See Fig. 4.) Then the loop is pulled upward and toward theneedle-hole in the clothplate, as is done by the hook when a new loop ofthread is taken from the needle and extended, the pressure on the bobbinis relieved, and the thread glides upward between the heel ot' thebobbin and the strap a without the least difficulty.

Nota-The phrase heel of the bobbin occurring in these specifications isintended to l refer to that portion of the bobbin which may at any timebe resting upon the shelf b and strap a.

Not meaning hereby to claim anything; lthat is covered by the patent ofJohn N. Wilkins, dated September 30, A. D. 1862,

What I claim as my invention, and desire to secure by Letters Patent,is-

l. Turning` the heel ofthe bobbn away from the rotating hook andsupporting it on the Vslide-ring', in the manner and for the purposesubstantially as described.

2. In combination with an eye-pointed needie and the rotating hook of asewing-machine,

WARREN MILLAR.

Witnesses HENRY BRooKEs, JOHN NUTT.

